Talking-machine record.



No. 862,407. PATENTED AUC. 6, 1907. 'I'. H. MACDONALD.

TALKING MACHINE RECORD.

APPLIOATION FILED JULYQ, 1906.

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THOMAS H.' MACDONALD, OF BRIDGEPORT, CONNECTICUT,ASSIGNOR TO AMERICAN GRAPHOPHONE COMPANY, OF BRIDGEPORT, CONNECTICUT, A CORPORATION OF w'Es'i VIRGNIA.

TALKING-MACHINE `RECORD.

Specification of Lettersv Patent.

Patented Aug. 6, 1907.

Application filed July 9', 1906. Serial No. 325.413.

4improvement is fully set forth in the following specification.

This invention has reference to the production of sound-records of disk form impressed in Celluloid. This material has long been recognized as having desirable properties oryuse as a sound-recording material, but it has not heretofore been employed commercially for the manufacture of disk records. -The reasons for this are mainly that Celluloid is too expensive to be'employed in a sheet of suflicient thickness t0 give-the desired rigidity, and although it has long been known that celluloid unites read-ily under heat and pressure with paper or cardboard, either with or without sizing, such compound disk quickly warps to such an extent as to spoil the appearance and usefulness of the l soundrecord. A

I have discovered that a commercially successful celluloid record can be made by inclosinga cardboard sheet between two sheets of Celluloid which areof the same thickness and quality. The uniformity of thickness and `quality of the Celluloid sheets is essential to prevent warping. j

In carrying out the inventionasheet of cardboard is placed between two thin sheets of celluloidfone of these sheets being slightly larger in diameter than the other sheet and the cardboard disk. i The three sheets are placed in the press, and compressed between the heated matrix and die in the usual way, therebyA impressing a sound-record in the surface of one of the celluloid sheets. The act of compression unites the three sheets in to a coherent'disk, and at the same time the projecting marginiof the wider Celluloid disk is drawn over the edge of the cardboard and against the edge of the other Celluloid disk. The'heat and pressure of the hydraulic press seal the edges of the two Celluloid sheets together. The disk is removed from the press and the slight surplus material is then removed in a rapidly revolving lathe. The result is asound-record composed of a cardboard disk hermetically sealed between two sheets of Celluloid. v

It is preferred that the under disk of Celluloid should have a roughened surface, such as produced by the use of a die Whose surface is covered by fine lines close together and crossing at right angles.

In the accompanying drawings, Figure 1 is a Crosssection illustrating the record in process of formation,

the thickness of the several Asheets being very much exaggerated. Fig. 2 is a planl View of part of the underside of a nished record showing the roughened surface. A represents the core of cardboard, which may or may not have the surfaces coated with sizing in the usual way of making a compound sheet of paper and celluloid.

B represents the facing sheet of Celluloid 'and C the lbacking sheet of Celluloid of the same thickness and quality as B.

The three sheets are placed between the die D and matrix E, the latter having on its surface a sound-record .in reverse, and are subjected to heat and heavy pressure in the usual way. By this means the sound-record is impressed in sheet B, and the three sheets are united together. Furthermore, the projecting margin of sheet B (which is slightly larger than sheet C) is drawn over the edge of the cardboard disk and united firmly tothe edge of sheet C.

The surface of the die D is roughened so as to produce on the back disk lC a roughened surface, such as shown in Fig. 2 consisting preferably of ne grooves intersecting at right angles. Instead of roughening the rear surface in this manner another sound-record may be impressed thereon. j

By this means a sound-record 'may be produced Whose total thickness is less than a sixteenth of an inch and will not warp under ordinary conditions of service and exposure. The product of this process'isl much lighter than the ordinarydisk record, and is not brittle as is the latter. Further advantages, however, are absence of extraneous sounds (the surface being a close approximation to absolute smoothness) andlgreatly increased durability. The Celluloid 'record will yield many times the number of reproductions that an ordinary record will give, and it shows, after a verylarge number of reproductions, no deterioration of quality. Moreover, it is not necessary with the new Celluloid record to change the needle after each reproduction. The needle may be used for a score or more times without detriment.

What is claimed is:

1. A sound-record of disk shape composed of two sheets of Celluloid nclosing between them land united to a sheet of'cardboard, said Celluloid sheets being of the same thickness and quality. l p

2. A sound-record of disk shape, composed of two sheets of Celluloid nclosing between them a sheet of cardboard, said Celluloid sheets being of the same thickness und quality, and being united at the edges so that the cardboard is entirely inclosed in a Celluloid envelop of uniform thickness.

3. A sound-record of disk shape composed of two sheets of Celluloid inclosing between them and united to a sheet of cardboard, said celluloid sheets bengof the same thickness and quality, one sheet having impressed in it fr soundrecord, and the other having its surface roughened. l 4. ,The method of makingl usound-record by placing a 5 cardboard disk betweentwo disks of Celluloid of the same thickness and quality, one celluloid disk being of slightly greater diameter thun the cardboard disk, applying, heat and pressure to the three disks, impressing a sound-record in the outer surface of one Celluloid disk, roughening the outer. surface of the other celluloid disk, and sealing the 10 cardboard entirely between the disks of Celluloid.

ln testimony whereof l have signed this-specification in the presence of two subscribing witnesses.

THOS. H. MACDONALD.

Witnesses:

BEssm J. BURR,

C. A. GIBNER. 

